Influence of Plastic Deformation Capacity on Failure Behaviour of Pipelines

5th Annual International Conference on Material Science and Environmental Engineering

材料科学;生态环境科学

Ma, Bin^1

Beijing Gas Group Research Institute, Beijing, China^1

关键词: Empirical formulas;    Limit bearing capacities;    Plastic deformation capacities;    Strain hardening model;    Strain-hardening exponent;    Uniform elongation;    Variation tendencies;    Yield to tensile ratios;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/301/1/012151/pdf
DOI  :  10.1088/1757-899X/301/1/012151

来源: IOP

【 摘 要 】

Plastic deformation capacity parameters affect the deformability of steel in the plastic stage, and then affect the limit pressure of pipelines. This paper investigates the influence of plastic deformation capacity parameters on the limit bearing capacity of pipelines. These parameters include yield to tensile ratio (σy/σu), percentage uniform elongation (δ) and strain hardening exponent (n). Based on the Swift strain hardening model, the relational expression of the plastic deformation capacity parameters is theoretically deduced. 95 groups of material tensile test datum have been collected. Based on these test data, the variation tendency of the plastic deformation capacity parameters have been analyzed statistically, and the empirical formula of the key parameters have been fitted numerically. 20 groups of finite element examples are designed to analysis the influence of yield to tensile ratio and uniform elongation to limit pressure of pipeline. Results show that, with the improvement of strength grade of steel, the plastic deformability of steel decreases; the recommended of critical plastic deformation capacity indexes are: pipeline steel below X65, σy/σuu